1. Field of the Invention
This invention relates to a corrosion-resistant member having a resistance to a plasma of a halogen based corrosive gas, a wafer-supporting member using the same, and a method of manufacturing the corrosion resistant member.
2. Description of Related Art
Processes requiring a chemical reaction become increased as fine machining more proceeds with the increase of a memory capacity in super LSI. Especially, in a semiconductor manufacturing apparatus requiring a super clean condition, a halogen based corrosive gas such as chlorine based gas, fluorine based gas or the like is used as a gas for deposition, etching or cleaning.
For example, when a heat CVD device or the like is used as a heating device in the semiconductor manufacturing apparatus for heating at a state of contacting with these corrosive gases, a halogen based corrosive gas such as ClF.sub.3, NF.sub.3, CF.sub.4, HF, HCl or the like is used as a gas for cleaning the semiconductor after deposition. And also, a halogen based corrosive gas such as WF.sub.6, SiH.sub.2 Cl.sub.2 or the like is used as a gas for forming a film at the deposition stage.
The inventors have disclosed in JP-A-5-251365 that an aluminum nitride sintered body provided on its surface with an aluminum fluoride layer has a high corrosion resistance against a plasma of the above halogen based corrosive gas. Namely, even when the aluminum nitride sintered body is exposed to, for example, ClF.sub.3 gas for one hour, no change of the surface state is observed.
Furthermore, the inventors have disclosed that an aluminum fluoride film is formed on the surface of the aluminum nitride sintered body by a gas phase method such as a CVD method or the like (JP-A-5-251365). And also, JP-A-7-273053 discloses that in order to prevent the occurrence of corrosion in a surface of an electrostatic chuck for a semiconductor wafer, the surface of the electrostatic chuck is previously subjected to a surface treatment replacing with fluorine to form AlF.sub.3 on the surface of the electrostatic chuck.
However, the inventors have made various studies and confirmed that when the aluminum nitride-base ceramic body is exposed to the halogen based corrosive gas such as ClF.sub.3 or the like in a high temperature range, particularly above 500.degree. C., the corrosion of the ceramic is promoted in accordance with the exposure condition to create particles.